Dual fuel injection pump control



Feb. 26, 1952' F. E. PELLY ET AL DUAL FUEL INJECTION PUMP CONTROL 2 SHEETSSHEET 1 INVENTOR 641?; f7. 6/? V BY FIEDGA/P PELLY F. E. PELLY ETAL DUAL FUEL INJECTION PUMP CONTROL Feb. 26, 1952 2 SHEETSSHEET 2 Filed April 27, 1948 8 r .5 Wm a TIP ..A Mi 1 a WW 1 RE U u s a 2 Y B a a 9 0 H3 fZO 26 A TTORNEY Patented Feb. 26, 1952 DUAL FUEL INJECTION PUMP CONTROL Francis Edgar Pelly, Upper Darby Township,

Delaware County, and Earl Russell Cave, Philadelphia, Pa.,

assignors to Baldwin-Lima- Hamilton Corporation, a corporation of Pennr sylvania Application April 27, 1948, Serial No. 23,414

8 Claims. (am-37 This invention relates generally to fuel injection systems for diesel engines and particular- 1y for dual fuel engines. As is well known in the art, dual-fuel engines use, instead of fuel oil, a gas of some kind, such as,'for instance, naturalxgas, which is admitted to the combustion chambers through the air intake manifold or in some other manner. Due to the nature of this gas, compression thereof in the combustion chambers does not cause its spontaneous ignition, as in the case of fuel oil, and accordingly auxiliary means are required to ignite it. While ignition means, such as an electric spark, have been used to accomplish this purpose, a more commonly employed means is the use of pilot charges of fuel oil injected into the combustion chambers by the usual injection pumps. This pilot charge of oil, being ignited by the temperature induced by the compression thereof in the usual manner, then ignites the gas.

The purpose of burning gas instead of fuel oil to make use of gas that may be readily and cheaply" available in thel'vicinity of the location of the engine, such as, for instance, in oil fields where natural gas is to be found in large volume,

and thus'avoid burning the more expensive fuel 'oil. To accomplish this economyas fully as possible, the pilot charge of-oil should be held to a minimum quantity consistent with being sufficient to assure the ignition thereof and of the gas in the combustion chambers. As some gases are more difficult to ignite than others, the amount of this pilot charge of oil varies and may range, for example, from five to twenty percent of the entire charge. Individual setting of the fuel pump control racks, according to the manufacturers calibrations thereon, to meter and deliver such a small quantity of oil through the pumps has proved to be inaccurate and unsatisfactory in the case of dual-fuel engines.

This is due to inexactness in the machining of pump parts and to inaccuracies in calibrating the fuel control racks, particularly in the range of calibrations indicating these smaller deliveries.

of oil where the curve of the helix of the pump plunger approaches the longitudinal. Setting the control racks of pumps of a dual-fuelengine according to these rack calibrations has resulted in the delivery of unequal quantities of 'oil, in the delivery of quantities of oil which are insufficient to cause ignition thereof when subjected to the temperatures and pressure of the com- .bustion chambers, and in the total failure of the pumps to deliver any oil. In addition, when a gas having a different B. t. u. content isto be used it is again necessary to adjust individual- 1y all the fuel control rack settings according to the rack calibrationswhich is both time-consuming and wasteful of oil. While the device disclosed herein may be used in any type of en- 'gine employing individual fuel injection. pumps,

- A further object is to provide improved means for not only establishing predetermined minimum quantities of fuel injection for dual operation but also for allowing complete flexibility of fuel control whereby the engine may be easily transferred to straight diesel operation. Other objects and advantages will be more apparentto those skilled in the art from the following description of the accompanying drawings in which:

Fig. 1 is aperspective view showing the cooperative relation between a conventional fuel injection pump of a dual fuel engine, a governor operatively connected thereto and means acting in conjunction with the control rack of such pump to effect the desired pump operation;

Fig. 2 is a diagrammatic side elevation of most ofthe elements shown in Fig. 1;

Fig. 3 is a diagrammatic plan view of a number of conventional fuel injection pumps, showing our improved combination therewith including means for simultaneously and equally varying the degree of minimum fuel injection; and Fig. 4 is a modification of the means for varying the degree of minimum fuel injection.

In the particular embodiment of the invention which is disclosed herein for the purpose of illusstrating one specific form among possible others that the invention might take in practice, we have shown in Figs. 1 and 2 one of a number of conventional fuel injection pumps I, of a dualfuel diesel engine which per se need not be described as it is well known in the art. Each pump has a usual fuel control rack Z slidable along its axis through the pump body and whose teeth, Fig. 3, mesh with a geared metering valve within the pump body. The details of such a metering valve are, of course, well known in the art and hence need not be disclosed except in their broader aspects ,as'illustrated herein. To vary the amount of oil delivered by the pump through an outlet pipe 3 to a spray nozzle and combustion chamber (notJshown), the control rack 2 is linearly advanced or retracted by a usual speed governors which has an oscillatable arm 5 connected through a link 6 to a collared arm I secured to a regulating shaft 8 for oscillating the same. The oscillating. motion; is: transmitted. to fuel control rack 2 first through. a collared lever 9 afixed to said shaft and provided with an adjusting screw 9a; then through a free? turning collared lever 10 provided. with a lug,

Illa, Figs. 1 and 2, engageable with adjusting screw 9a; and finally a link H. connecting col-r.- lared lever ill with fuel controlrack 2. Such motion of the regulating shafteither advances the rack to the left, as viewed in Figs; 1 and 2, to increase the fuel delivery, or retracts the rack to the right to diminish such delivery. Disposed. about regulating shaft 8 and positioned between free-turning collared lever Ill and a spring collar. l2 affixed to said shaft is a torsion spring 12a adapted. and arranged to bias. the outer, end of collared lever ID: to the right to exert a continuous yielding pressure in a. fuel reducing direction. against control rack 2 through; link If. As shown in Fig.1, governor 4', through regulating shaft 8, a collared lever l3 afiixed to said shaft, a link M, and a lever l5, also performs the iUnC-r tion of operating a spring-loaded butterfly valve 16 in. a. gas supply line I'lto regulate. the flow of gas therethrough to the. combustion chambers L in accordance. with the demands: of the engine. As: the. construction and operation of this type of fuel injection pump and of the governor. to control the oil through therpumps. and the gas to the combustion chambers'are: well-known and understood in theart, it is deemed unnecessary to describe either further.

To overcome the. difficulties incident to the necessity of having; extreme nicety of pump control for dual. fuel operation we provide means consisting of a stop lever iii of any suitable contour but preferably that shown. in. Figs. 1 and 2., which is pivotally mounted on a pin-2|. in a. bi furcated arm IS of a bracket 20. A curvededge 2-2 of. stop lever. l8 not only provides. a line con tact with the end. of the. rack so that stop. lever l8 may be rotated with a minimum of friction while in contact with the rack, but is also so offset with respect to fulcrum pin. 21 that a portion of such curved edge is. advanced or retracted-by said rotation. Bracket28 preferably clamped to the fuel injection pump body at. a..convenient point beneath the fuel control rack by a separable clamping ring 23 carrying a mounting member 24' tov which the bracket issecured by boltsv 25... Shims 26 may be interposed betweenthe bracket and mounting member to insure exact initial positioning of surface 22- relative to control rack 2 in order. to obtain. the precise minimum amount ill of fuel for dual fuel operation. After. this minimum amount is determined for one particular pump, the. stop lever I8 is lockedin that position by aremovable lock pin. 21, of any suitable design, extending through the stop: lever and bracket 2%. While wehave described apparatus of our device as applying to a single fuel injection pump, it is of course understood that identical apparatus is similarly applied toeach of. the other. pumps of an. engine and that. the stop lever (B. of" each pump will be individually adjusted and locked by a pinfor dual fuel operation.

The stopv means for the several pumps are then connected together to function. equally, simultaneously and by meansof a single control. To do this, there extends beneath brackets 20. and stop levers is of all the pumps a common control shaft 28 mounted inbearings 22, one of which is split; This control shaft is manually rotatable by any convenient means, such as, for instance, a. knurled wheel 39 attached to the shaft, and can be locked in any position against movement by any suitablemeans, such as, a screw 3i threaded through the. farther of the. two. extended ends of split bearing 29. This control shaft carries a plurality of adjustable collared levers 32, the free ends of which are connected to the outer ends of all stop levers Is by links 33. When the foregoing. connections. are fully made, the lock pins 2] arethenremoved, whereupon rotation of control shaft 28. by wheel 30 in one or the other direction causescurvededges 22 of all stop levers 18, through this linkage means, to be simultaneously advanced or retracted equal distances.

operationr- 'lhe method of assembly and operation of our device are as follows: With the fuel injection pumps removed from the engine, clamping rings 2.3 carrying mounting. members are fastened. to thepump body. Disregardin the. manufacturers. calibrations on. the. fuel. con trol racks, each piunpisthen tested, by a process of. trialfand. error, tometer andfdeliver a certain estimated quantity of. fuel oil per minute, which estimated amount is believed, to be the least amount that. will ignite under pressure in the combustion chambers. Holding the fuel control rackinthis adjusted position and with removable lockpin 21 in position to holdstop lever 18 and bracket 25 relatively immovable, bracket 20 is then secured to mounting member 24 by bolts 25 so that curved edge 22 is in contact with the free end. of fuel control rack 2. To obtain a precise fit of curved edge 22 with fuel control rack 2, it may be necessary to interpose shims 26 between the bracket. and the mounting member to be held in place by the pressure ofbolts 25, Fig. 3. With bracket. 29' secured to mounting member 24, the rack. is yieldingly held against stop lever l8 by the force of torsion spring 52a acting through freerturnin'g lever f0 and link IL. When allthe pumpsof the engine have beenindividuallytested and adjusted in the manner described above so that all pumps meter and deliver precisely-the same amount, the pumps are. then mounted on the engine and secured thereto, in their usual positions. Control shaft28 on which have been previously mounted enough levers-32' to provide one for each stop lever [B is next, locked against turning; by tightening-screw 3|. Links 33 are then connected to stop levers, l8 and to levers 3'2 and levers 32 secured to the control shaft. With the. completion of these linkage'assemblies, lock pins 21 are removed. Owing to the fact that control shaft 28' is'locked againstmovement and that no playis provided in the linkage means between the control shaft and the stop levers, the removal of lock pins 21 does not alter the adjusted'positionsof the stop levers and the stop levers, thus rigidly held by'saidilinkage means, act as stops to prevent the racks fromnioving beyond the point determined by said tests to be the position in which the rack will meter and deliver said estimated quantity of oil through each pump. The advancing of the racks in this manner has had the effect of increasing the gaps between adjusting screws ta and lugs ifla so that it now becomes necessary to'decrease this distance, which is done merely by means of said adjusting screws.

vIf the estimated quantity of oil to be delivered through each pump proves-sumcient to operate the engine efliciently and economically, no-adjustment of our device is necessary. The pumps operate in the usual manner with the exception that the fuel control racks. are now prevented by said stop levers from being retracted beyond the point at which they were set by said test to deliver not less than said. estimated quantity of oil. The racks may also be moved in the other direction by action of the governor in the usual manner, as when an additional load is placed on the engine or when the gas supply is reduced or cut oif entirely. In these instances, as the engine slows down, the governer rotates regulating shaft 8 in a counterclockwise direction, as viewed in Figs. 1 and 2, the first part of said movement actuating butterfly valve I3 in gas supply line H, the latter part of said movement actuating all fuel control racks through adjusting screws 9a, lugs lfia, freeturning levers H3, and links H. The movements of all racks are simultaneous and equal, resulting in the maintenance of relatively equal deliveries of oil through the pumps. Should this estimated quantity of oil prove insufiicient to cause ignition, or should a gas of poorer quality be used, requiring a greater percentage of fuel oil to cause igni- H tion, control shaft 28 would be unlocked by loosening screw 3!, then rotated by wheel 39 in a counterclockwise direction until curved edges 22 were advanced to force spring-loaded fuel con: 'trol racks 2 to a point where the pumps would meter-and deliver larger but still relatively equal amounts of oil. The control shaft would then be relocked in this new position. Conversely, in the event a better quality gas were used, the control shaft, after being unlocked, would be rotated in a clockwise direction, retracting stop levers IS and allowing fuel control racks 2 to move back under action of torsion spring l2a so that all pumps would then deliver smaller but st ll relatively eoual quantities of oil, the control shaft then being relocked. These adjustments of the stop levers to these new minimum delivery settin s can be made while the engine is running.

The modificat on of our invention, shownin Fig. 4, may be em lo ed in instances where the space between the fuel in ection pum s and the en ine wall is insufii ient to accommodate the outwardly extending levers of the preferred form.

In this modification, stop leve s i8, now shortened longitudinally, a e fixedly mounted on rotatahle 'fulcrum pins 2! between arms IQ of brackets which are adjustahlv secured to the pump body, as in the preferred form. Secured to an a ial extension of each fulcrum pin 2| is a le er 34 which is connected to a common control shaft 28' by a link 35 and an ad ustable lever 36. Rotation of common control shaft 28' in a counterclockwise direction advances a curved edge 22' of stop lever l8, forcin spring-loaded fuel control rack 2' forward to meter and deliver a greater minim m cuantitv of oil, while rotation of the shaft in the other direction retracts curved edge 22 allowing the sprin -loaded rack to move backwa dly to meter and deliver a lesser minimum quantity of oil. For mounting purposes, bra ket 20' is provided with a lock pin 21'. As in the preferred form, each pump of an engine is equipped with a stop lever and means connecting the stop lever with the control shaft so that all stop levers may be advanced or retracted sim ltaneously and equally by means of the control shaft. Also, as in the preferred form, all pumps are first tested and adjusted to meter and deliver identical quantities before the stop levers a e mounted thereon. It should be understood that the control shaft in both modified and preferred forms may be disposed either as shown in the drawings, or positioned in front of the fuel injection pump, or in any other OOH. venient position, depending on the space available in the vicinity of the pumps, the linkagemeans in both cases being readily adaptable to almost any position of the control shaft.

I through the pumps, as has been described above, it is readily seen that our adjustable stop means may also be used, without modification, with the fuel injection pumps of engines burning fuel oil exclusively to advance or retard the idling speed of the engine.

pumps of both dual-fuel and single-fuel diesel engines, whereby all pumps after being tested and adjusted to meter and deliver equal quantities of fuel oil, will be held to meter and deliver not less than such quantities, and whereby such minimum quantities may be simultaneously and equally increased 01' decreased during the operation of the engine.

It will, of course, be understood by those skilled in the art that various changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as set forth in the appended claims.

We claim:

1. The combination in a fuel injection control apparatus for internal combustion engines having injection pumps and a no mally movable pump control element for varying the pump discharge comprising, stationary means for limit ing movement of said pump control element so that a predetermined minimum pump discharge may be effected, means for varying the limiting position of said lmit means so as to vary said predetermined minimum discharge, and means movable relative to said limiting means for operatin said normally movable pump element while the limiting means remains stationary, thereby to increase the pump discharge whenever desired, said means for limiting movement of the pump control element including oscillatable members, one for each pump, and the means for varying the limiting position of the limit means including an element commonly connecting said oscillatable members together so that the same may be simultaneously and uniformlv actuated.

2. The combination in a fuel injection control apparatus for internal combustion engines havinjection pumps and a normally movable pump control element for varying the pump discharge comprisingstationary means for limiting movement of said pump control element so that a predetermined minimum pump discharge may be effected, means for varying the limiting position of said limit means so as to vary said predeterm ned minim m discharge, and means movable relative to said limiting means for operating said normally movable pump element ,while the limiting means remains stationary, thereby to increase the pump discharge whenever desired, said movable pump control elements being spring biased in a direction to reduce the pump discharge, and the means for limiting movement of such pump control elements including members, one for'each pump, providing abut- 4. The combination in a fuel injection control apparatus for internal combustion engines having injection pumps and a normally movable pump control element for varying the pump discharge comprising, stationary means for limiting movement of said pump control element so that a predetermined minimum pump discharge may be effected, means for varying the limiting position of said limit means so as to vary said predetermined minimum discharge, and means movable relative to said limiting means for operating said normally movable pump element while the limiting means remains stationary, thereby to increase the pump discharge whenever desired, said movable pump control elements being spring biased in a direction to reduce the pump discharge, and the means for limiting movement of such pump control elements including pivoted members adapted to provide abutments against which said movable elements are yieldably pressed to define the minimum discharge, the abutment portion of said pivoted members being offset from the pivotal axes so as to swing in an arc toward or away from the pump control element and thereby control the extent of minimum pump discharge.

5. The combination in a fuel injection control apparatus for internal combustion en ines having injection pumps and a normally movable pump control element for varying the pump discharge comprising, stationary means for limiting movement of said pump control element so that a predetermined minimum pump discharge may be effected, means for varying the limiting position of said limit means so as to vary said predetermined minimum discharge, and means movable relative to said limiting means for operating said normally movable pump element while the limiting means remains stationary, thereby to increase the pump discharge whenever desired, said movable elements of the injection pumps being spring biased in a direction to reduce the pump discharge, and the means for limiting movement of such pump control ele.- ments including pivoted members adapted to provide abutments against which said movable elements are yieldably pressed to define the mini mum discharge, the abutment portion of said pivoted members being oifset from the pivotal axes, and the means for varying the limiting position of said abutting portions including an oscillatableshaft; commonly connected by levers and links to the respective pivotal members.

6. The combination in a fuel injection control apparatus for internal combustion engines h-aving injection pumps and a normally movable pump control element for varying the pump discharge comprising, stationary means for limiting movement of said pump control element so that a predetermined minimum pump discharge may be effected, means for varying the limiting positionof said limit means so as to vary said pre-- determined minimum discharge, and means movable relative to said limiting means for operating said normally movable pump element while the limiting means remains stationary, thereby to increase the pump discharge whenever desired, said movable elements of the injection pumps being spring biased in a direction to reduce the pump discharge, and the means for limiting movement of such pump control elements including pivoted members adapted to provide abutments against which said movable elements are I Number yieldably pressed to define theminlmum discharge, the abutment portion of said pivoted members being offset from the pivotal axes, and the means for varying the limiting position of said abutting portions, including an oscillatable shaft commonly connected by levers and links to the respective pivotal members and the levers having releasable connections with said shaft whereby the abutment members may be separately adjusted in accordance with the individual pump characteristics.

'7. The combination in a fuel injection control apparatus for internal combustion engines having injection pumps and a normally movable element for varying the pump discharge comprising, a plurality of members, one for each pump, adapted to providev abutment surfaces for individually engaging said pump control elements to determine a desired minimum discharge for each pump, means for movably supporting said abutment members so that said surfaces are movable to provide a variable distance through which said pump control elements must move before engaging said surfaces and thereby adjust the amount of minimum discharge of each pump individually, and means for commonly actuating said members so that their abutment surfaces simultaneously effect the same degree of minimum discharge position for all pumps.

8. The combination in a fuel injection control apparatus for internal combustion engines having injection pumps and a normally movable element for varying the pump discharge com.- prising, a plurality of members, one for each pump, adapted to provide abutment surfaces for individually engaging said pump control elements to determine a desired minimum discharge for each pump, means for movably supporting said abutment members so that said surfaces are movable transversely of the direction of movement of the pump control elements to provide a variable distance through which said pump control elements must movebefore engaging said surfaces and thereby adjust the amount of minimum discharge of each pump individually, and means for commonly actuating said members so that their abutment surfaces simultaneously effect the same degree of minimum discharge position for all pumps.

FRANCIS EDGAR PELLY. EARL RUSSELL CAVE.

REFERENCES CITED The following references areof record in the file of this patent:

UNITED STATES PATENTS Name Date 1,497,258 Beals ,June 10, 1924 2,159,360 Starr et a1 May 23, 1939 2,360,526 Staples Oct. 17, 1 944 FOREIGN PATENTS Number Country Date 280,756 Italy 1930 473,017 Great Britain 1935 OTHER REFERENCES New York, N. Y., page 37. 

